Dentists, otolaryngologists and other health care professionals use a variety of instruments in examining the ears, nose, throat, mouth etc. Particularly with reflective instruments such as mirrors, it is desirable to elevate the temperature of the instrument to above body temperature so that the patient's breath does not fog the mirror. It is also desirable to elevate the temperature of various instruments which touch the patient for added comfort and to prevent sudden movements of the patient which might take place in reaction to contact with a cold instrument.
A number of devices have been proposed in the prior art for warming instruments such as mirrors used in the examination of patients. One type of device is a free-standing or self-contained mirror warmer comprising a housing having internal heating elements and an opening for receiving the end of the instrument which mounts the mirror. Units of this general type are disclosed, for example, in Folland U.S. Pat. No. 4,241,290; Carleton et al. U.S. Pat. No. 4,278,870; and Beitner U.S. Pat. No. 4,092,138.
One problem with mirror warmers of the type described above is that these units are free-standing and must be placed atop the treatment cabinet or other furniture in the immediate area of the patient examination chair. This takes up valuable space which otherwise could be used for other equipment necessary for examination of the patient. Another problem with mirror warmers of this type is that only the mirror itself and possibly a portion of the handle of the instrument are heated by the warming device. When the instrument is removed from the mirror warmer, the remainder of the handle acts as a heat sink to draw heat away from the mirror end of the instrument, thus lowering the temperature of the mirror. If the physician or dentist delays using the mirror even for a relatively short period of time, its temperature may have decreased to the point where the mirror would become fogged by the patient's breath.
Another type of apparatus employed in the prior art for warming instruments such as mirrors is a treatment cabinet having a series of lightbulbs or similar heating elements mounted to the back wall of the cabinet, in a space between the drawers and back wall, to increase the overall temperature of the interior of the cabinet within which the instruments are stored. Apparatus of this type have the advantage of keeping the instruments in a closed drawer within the treatment cabinet to avoid contamination, but a number of problems are created.
The use of lightbulbs or other heating elements mounted to the back wall of the cabinet is an extremely inefficient and costly means to heat the interior of a treatment cabinet and the instruments therein. The heat produced by the lights or heating elements must move by conduction or convection along the entire area of the drawer or other part of the cabinet which holds the instruments. In most cases, the entire interior of the cabinet is heated whereas the instruments are usually stored in only a small area therein. This wastes a substantial amount of power and is inefficient in heating instruments located furthest from the back wall of the cabinet.